Bug 160600 - Accessing automounted directories can cause a process to hang forever
Accessing automounted directories can cause a process to hang forever
Status: CLOSED ERRATA
Product: Red Hat Enterprise Linux 3
Classification: Red Hat
Component: kernel (Show other bugs)
3.0
All Linux
medium Severity medium
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Assigned To: Jeff Moyer
Brock Organ
:
: 180343 (view as bug list)
Depends On:
Blocks: RHEL3U8CanFix
  Show dependency treegraph
 
Reported: 2005-06-15 19:54 EDT by Jeff Moyer
Modified: 2007-11-30 17:07 EST (History)
4 users (show)

See Also:
Fixed In Version: RHSA-2006-0437
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Environment:
Last Closed: 2006-07-20 09:24:35 EDT
Type: ---
Regression: ---
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CRM:
Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---


Attachments (Terms of Use)
Fix a race in the tail end of an expire event, causing a process to hang forever. (979 bytes, patch)
2005-06-15 19:54 EDT, Jeff Moyer
no flags Details | Diff

  None (edit)
Description Jeff Moyer 2005-06-15 19:54:25 EDT
Description of problem:
Automount can cause a program to hang when accessing a directory that is being
expired.

Version-Release number of selected component (if applicable):
autofs-4.1.3-130
kernel-2.4.21-32

How reproducible:
No reproducer available.

Steps to Reproduce:
1.
2.
3.
  
Actual results:
If the race is triggered, the process performing the lookup will hang
indefinitely.  You will be able to interrupt it, though.

Expected results:


Additional info:
This issue was reported upstream, and is resolved with the attached patch.  The
race is pretty clear, once you understand the code path, and the fix looks
straight forward and correct.
Comment 1 Jeff Moyer 2005-06-15 19:54:25 EDT
Created attachment 115514 [details]
Fix a race in the tail end of an expire event, causing a process to hang forever.
Comment 2 Jeff Moyer 2005-06-15 19:55:05 EDT
Posting patch to internal mailing list for review.
Comment 3 Ernie Petrides 2006-02-15 19:49:42 EST
A fix for this problem has just been committed to the RHEL3 U8
patch pool this evening (in kernel version 2.4.21-40.1.EL).
Comment 4 Ernie Petrides 2006-04-28 17:42:31 EDT
Adding a couple dozen bugs to CanFix list so I can complete the stupid advisory.
Comment 6 Jeff Moyer 2006-05-03 13:56:51 EDT
*** Bug 180343 has been marked as a duplicate of this bug. ***
Comment 7 Joshua Giles 2006-05-31 13:48:30 EDT
I do see "no reproducer available," however can you provide steps you used
to make it reproduce in your environment?
Comment 8 Jeff Moyer 2006-05-31 20:27:28 EDT
You could setup a simple map with a low timeout (say 5 seconds).  Then, have a
script constantly access the mount point at 5 second intervals.  Ensure that
mounts and unmounts are occurring.  If not, up the script interval to 6 seconds.
 The unmount/mount pair must occur quite close to each other.
Comment 10 Red Hat Bugzilla 2006-07-20 09:24:36 EDT
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2006-0437.html

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